Yersiniosis is a bacterial infection that can cause acute stomach illness. Yersiniosis is caused by infection with Yersinia pseudotuberculosis or Yersinia enterocolitica.


Yersiniosis is spread by:

  • contact with infected faeces (poos)
  • eating or drinking contaminated food or water
  • contact with contaminated soil or infected animals, especially pigs.

If you’ve been infected, it usually takes 5–10 days for the symptoms to develop but can take up to 21 days.

The disease can still be present in faeces weeks after the symptoms have gone.

Foods that have been known to cause outbreaks of yersiniosis include pork, raw grated carrots, lettuce and contaminated milk.

Infections from Yersinia enterocolitica are often linked to pork products, and in New Zealand have been linked with sushi. Although optimal growth is seen at 28–30°C, Yersinia enterocolitica also grows well in a refrigerator (4°C) and survives freezing.

The third Yersinia species that causes illness in humans is Yersinia pestis. This is the organism that causes plague. It hasn’t been reported in New Zealand since 1911.


Symptoms of Yersinia pseudotuberculosis include:

  • abdominal pain (often on the lower right), which may mimic appendicitis
  • fever
  • sometimes diarrhoea.
  • Rash and joint pain, appearing 1-3 weeks later. Joint pain can last up to 6 months.
  • In rare cases sepsis (infection in the blood). This is more common in people with weakened immune systems.

Symptoms of Yersinia enterocolitica vary between younger children and older children and adults. For children under 5, symptoms include:

  • diarrhoea
  • vomiting
  • fever
  • less commonly, abdominal pain.

Older children and adults are more likely to experience abdominal pain as the prominent symptom. Bacteraemia (bacteria in the blood) and sepsis (infection in the blood, sometimes called blood poisoning) may occur in immunocompromised individuals.

See your doctor or call Healthline on 0800 611 116 for advice if you think you might have yersiniosis. There’s a laboratory test which can check for the disease.


Yersiniosis is not usually serious and most people recover quickly.  Anyone with diarrhoea should drink extra fluids to avoid dehydration. Children with diarrhoea, who vomit or who refuse extra fluids should see a doctor. Anyone with prolonged or severe diarrhoea, or who has symptoms causing concern should see a doctor.

A doctor may recommend antibiotics in selected cases.


Yersiniosis is rare in New Zealand. These tips can help you protect your family from yersiniosis and other foodborne illness.

  • Wash fresh fruit and vegetables before eating.
  • Avoid eating raw or undercooked meat.
  • Only use pasteurised milk or milk products.
  • Wash hands well with soap and water and dry well:
    • before eating and preparing food
    • after handling raw meat
    • after contact with animals
    • after going to the toilet or changing nappies.
  • Prevent cross-contamination in the kitchen by:
    • using separate cutting boards for meat and other foods
    • carefully cleaning all cutting boards, counter-tops and utensils with soap/detergent and hot water after preparing raw meat.
    • cooking meat thoroughly.
  • Care should be exercised when around animals, in particular when they are ill.
    • Wash hands and dry hands well after contact with animals.
    • Supervise young children during contact with animals and during hand cleaning.
    • Food-related activities should be separate from areas with animals.
    • Domestic animals with diarrhoea should be taken to a vet for assessment and treatment.
    • Dispose of animal faeces in a sanitary manner.
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